Integrated thermal management system

Abstract

An integrated thermal management system for a fuel cell electric vehicle is disclosed. The integrated thermal management system includes a fuel cell system, a brake resistor, a fuel cell coolant loop that includes a fuel cell radiator thermally and fluidly coupled to the fuel cell system, a brake resistor coolant loop that includes a brake resistor radiator thermally and fluidly coupled to the brake resistor, and a heat exchanger loop that includes a coolant-coolant heat exchanger thermally and fluidly coupled to the fuel cell coolant loop and the brake resistor coolant loop. In a fuel cell cooling operating mode, heat is transferred from the fuel cell system to an ambient environment through the fuel cell radiator and the brake resistor radiator.

What is claimed is: 
     
         1 . An integrated thermal management system for a fuel cell electric vehicle, comprising:
 a fuel cell system;   a brake resistor;   a fuel cell coolant loop comprising a fuel cell radiator thermally and fluidly coupled to the fuel cell system;   a brake resistor coolant loop comprising a brake resistor radiator thermally and fluidly coupled to the brake resistor; and   a heat exchanger loop comprising a coolant-coolant heat exchanger thermally and fluidly coupled to the fuel cell coolant loop and the brake resistor coolant loop,   wherein, in a brake resistor cooling operating mode, heat is transferred from the brake resistor to an ambient environment through the brake resistor radiator, and   wherein the brake resistor radiator is positioned upstream from the coolant-coolant heat exchanger.   
     
     
         2 . The integrated thermal management system of  claim 1 , wherein the fuel cell coolant loop comprises a first coolant and the brake resistor coolant loop comprises a second coolant. 
     
     
         3 . The integrated thermal management system of  claim 2 , wherein, in the brake resistor cooling operating mode, heat is transferred from the second coolant to the ambient environment through the brake resistor radiator. 
     
     
         4 . The integrated thermal management system of  claim 3 , wherein, in the brake resistor cooling operating mode, heat is transferred from the second coolant to the first coolant in the coolant-coolant heat exchanger. 
     
     
         5 . The integrated thermal management system of  claim 4 , wherein, in the brake resistor cooling operating mode, heat is transferred from the first coolant to the ambient environment through the fuel cell radiator. 
     
     
         6 . The integrated thermal management system of  claim 1 , further comprising a heating, ventilation, and air conditioning (HVAC) coolant loop thermally and fluidly coupled to the brake resistor coolant loop. 
     
     
         7 . The integrated thermal management system of  claim 6 , wherein, in the brake resistor cooling operating mode, the HVAC coolant loop is bypassed. 
     
     
         8 . The integrated thermal management system of  claim 1 , wherein the fuel cell radiator is positioned downstream from the coolant-coolant heat exchanger. 
     
     
         9 . The integrated thermal management system of  claim 5 , wherein a bypass valve is operative such that a first portion of the first coolant is routed through the fuel cell radiator and a second portion of the first coolant is routed through a bypass line. 
     
     
         10 . The integrated thermal management system of  claim 9 , wherein the bypass valve is configured with multiple positions to allow the first portion of the first coolant and the second portion of the first coolant to have a selected ratio therebetween. 
     
     
         11 . The integrated thermal management system of  claim 6 , wherein, in the brake resistor cooling operating mode, heat is transferred from the brake resistor to the HVAC coolant loop and to the fuel cell coolant loop. 
     
     
         12 . The integrated thermal management system of  claim 11 , wherein, in the brake resistor cooling operating mode, the fuel cell coolant loop heats the fuel cell system when the ambient environment around the fuel cell electric vehicle has a temperature of 5 degrees Celsius or below. 
     
     
         13 . The integrated thermal management system of  claim 11 , wherein, in the brake resistor cooling operating mode, the HVAC coolant loop heats a cabin heater core. 
     
     
         14 . The integrated thermal management system of  claim 13 , wherein, in the brake resistor cooling operating mode, a fan transfers heat from the cabin heater core to a cabin of the fuel cell electric vehicle. 
     
     
         15 . An integrated thermal management system for a fuel cell electric vehicle, comprising:
 a fuel cell system;   a brake resistor;   a fuel cell coolant loop comprising a fuel cell radiator thermally and fluidly coupled to the fuel cell system;   a brake resistor coolant loop comprising a brake resistor radiator thermally and fluidly coupled to the brake resistor, wherein the brake resistor loop comprises an expansion tank; and   a heat exchanger loop comprising a coolant-coolant heat exchanger thermally and fluidly coupled to the fuel cell coolant loop and the brake resistor coolant loop,   wherein, in a brake resistor cooling operating mode, heat is transferred from the brake resistor to an ambient environment through the brake resistor radiator.   
     
     
         16 . The integrated thermal management system of  claim 15 , wherein the fuel cell coolant loop comprises a first coolant and the brake resistor coolant loop comprises a second coolant. 
     
     
         17 . The integrated thermal management system of  claim 16 , wherein, in the brake resistor cooling operating mode, heat is transferred from the second coolant to the ambient environment through the brake resistor radiator. 
     
     
         18 . The integrated thermal management system of  claim 17 , wherein, in the brake resistor cooling operating mode, heat is transferred from the second coolant to the first coolant in the coolant-coolant heat exchanger. 
     
     
         19 . The integrated thermal management system of  claim 18 , wherein, in the brake resistor cooling operating mode, heat is transferred from the first coolant to the ambient environment through the fuel cell radiator. 
     
     
         20 . An integrated thermal management system for a fuel cell electric vehicle, comprising:
 a fuel cell system;   a brake resistor;   a fuel cell coolant loop comprising a fuel cell radiator thermally and fluidly coupled to the fuel cell system;   a brake resistor coolant loop comprising a brake resistor radiator thermally and fluidly coupled to the brake resistor;   a heat exchanger loop comprising a coolant-coolant heat exchanger thermally and fluidly coupled to the fuel cell coolant loop and the brake resistor coolant loop; and   a heating, ventilation, and air conditioning (HVAC) coolant loop thermally and fluidly coupled to the brake resistor coolant loop,   wherein, in a brake resistor cooling operating mode, heat is transferred from the brake resistor to an ambient environment through the brake resistor radiator, and   wherein, in the brake resistor cooling operating mode, the HVAC coolant loop is bypassed.